An electromagnetic valve disclosed in Patent Document (JP H4-331881 A) is a device capable of switching a flow pathway in which a working fluid flows. According to the electromagnetic valve of the Patent Document, at the time of non-energization thereof, a ball valve presses a valve seat due to an applied pressure of a working fluid flowing from an inflow passage and closes the electromagnetic valve while a drain valve portion of a shaft keeps a drain port sheet in a valve opening state. At the time of energization of the electromagnetic valve, an electromagnetic force from a solenoid portion causes the shaft to move toward the ball valve and press the ball valve. Thus, the ball valve is removed from the valve sheet, and the electromagnetic valve is opened. The drain valve portion of the shaft closes the drain port sheet.
In the electromagnetic valve of the Patent Document, a pressure applied to the ball valve increases with increase in supply pressure of the working fluid. Thus, a necessary force for driving the shaft and causing the fluid to flow from the inflow passage through a communication passage to a discharge passage may increase. In order to enhance the force for driving the shaft, a method to increase a magnetic force is enlarging of a size of the solenoid portion, but an entire size of the electromagnetic valve may become large in this case. Further, if a cross-sectional area of the communication passage is reduced, a flow rate characteristic of the electromagnetic valve may deteriorate.